Ringboat



March 1, 1966 A. E. MOORE 3,237,218

RINGBOAT Filed Aug. 17, 1964 6 Sheets-Sheet 1 ALVkN EDWARD MOORE,

INVENTOR.

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ATTORNEY FiG' l March 1, 1966 A. E. MOORE 3223?a218 RINGBOAT Filed Aug. 17, 1964 6 Sheets-Sheet 2 I111! nm A 56 42 ll 44 6 4e 5'! 5. ii A r A A;. A A n 55 FIG: 2 A 50 FIG. 3

ALVlN EDWARD MOORE, ag TNVEN TOR.

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FIG. 9

v o a M m w E N v a.

INVENTOR.

FIG- 7 A? TORNEV.

' March 1, 1966 A. E. MOORE 3,237,238

RINGBOAT Filed Aug. 17. 1964 6 Sheets-Sheet 4 I78 93 I63 FIG. \0

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INVENT OR.

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A. E. MOORE March 1, 1966 RINGBOAT 6 Sheets-Sheet 5 Filed Aug. 17, 1964 ALV\N EDWARD MOORE,

ATTORNEY.

6 Sheets-Sheet 6 A. E. MOORE RINGBOAT March 1, 1966 Filed Aug. 17. 1964 United States Patent 3,237,218 RINGBOAT Alvin Edward Moore, 916 Beach Blvd, Waveland, Miss. Filed Aug. 17, 1964, Ser. No. 389,974 32 Claims. (Cl. 9-2) This invention pertains to a light-weight boat or other means of transportation over water. It is entitled Ringboat because it utilizes curved-surface containers of gas to increase the buoyancy, speed and safety of a water vessel.

Two major problems in boat and ship building are: obtaining safety against capsizing and wreck; and reduction of the propelled crafts friction, waves and eddies. Safety is largely a matter of the positions of the centers of buoyancy and gravity and preventing leaks. Narrow water craft, designed for speed, sometimes capsize because the center of buoyancy is lower than the center of gravity, and when the vessel rolls extremely the center of buoyancy does not shift far enough to counteract the turning moment from the center of gravity. This defect has long been somewhat obviated in catamarans, but these, as built to date, have been more subject to breaking up in rough water than the more compact one-piece craft. One reason for this is a lack of suflicient flexibility for the hulls and their connections to yield, without breaking, and then to spring back to their desired shape. A flexible and unusually strong catamaran of generally conventional design would help solve this problem of safe stability, but unless extraordinarily built it would still be subject to breaking apart and have the defect of a low center of buoyancy.

A key to the best solution of this problem lies in a change from the time-honored marine engineering concept of buoyancy. This should not merely consist of the buoyancy of lighter-than-water parts, but should also comprise a lighter-than-air factor. Part of a thoroughly safe vessel, with little tendency to roll and surety of righting itself from all rolls, would be a lighter-than-air structure located at least in part above the waterline and containing helium, other lighter-than-air gas, or vacuums.

The other major component of the problem of safetyof preventing the springing of leaksinvolves the tendency of all vessels to bend. Some are subject to sagging (bending down at their centers), and others to hogging (bending down at their ends). In rough weather this tendency is multiplied, and it and the local effect on a rigid skin of the crash of waves cause leaks. The danger from these is aggravated by the fact that most boats and ships have only a few watertight and buoyant air spaces, which usually are partly filled with machinery, cargo and people. A remedy for this disadvantage lies in the provision of a relatively large number of scaled buoyant chambers. These should be light in weight, and should provide part of the structural strength of the hull. Moreover, a leak may be prevented in the first place by making the hull of both waterproof and flexible material. A fish, being yieldable and resilient, never breaks apart. Nor does the inflated inner tube used by a child at the seashore.

Such flexibility also aids in solving the problem of reduction of friction when underway. At low speeds, surface or skin friction is the cause of nearly all the resistance to marine propulsion. The dolphins speed, amazing for its energy, is to a large extent due to the flexibility of its skin.

Another and most important way of lessening friction is to reduce the area of the vessels wet surface. This may be achieved to a certain extent by making the bottom of a slim hull semi-cylindrical in cross section, and above this bottom portion providing an upper portion of straight, parallel sides, between a streamlined bow and stern. But

a more effective means of reducing the wet surface is to lift part of the hulls bottom portion out of the water by lightetr-than-air, balloon-like elements.

In view of the above facts, an object of the present invention is to provide a water vehicle having a center of buoyancy that has a lighter-than-air factor.

Another object of the invention is to provide a lightweight boat or other water-traversing vessel that has a lighter-than-air lifting power and a relatively small area of wet surface.

A further object is to provide a catamaran having flexible hulls or floats, that are flexibly but strongly joined by a central resilient portion.

Another object is to provide a vehicle that comprises, in its body structure, gas-inflated tubes of flexible waterproofed fabric.

A further object is to provide a vehicle having a body structure that comprises rubber-and-fa-bric tubes, inflated with air or other cheaply-obtained gas, and lift-producing containers of helium, other light-weight gas or vacuums, floating within the rubber-and-fabric tubes.

Another object is to provide a vehicle having a flexible body structure that comprises porous, gas-containing rubber or other plastic and aerostatic, lift-providing containers within the rubber, each container being made of solid material that is substantially impermeable to gas, and con taining a vacuum, or lighter-than-air gas or mixture of gases.

A further object is to provide a watercraft whose structure largely comprises used, inspection-rejected or surplus tires or tubes of automobiles or other vehicles.

The foregoing and other objects of the invention will become more fully apparent from the following detailed description of the inventive structure and from the accompanying drawings, in which:

FIGURE 1 is an elevational view in section, partly broken away, thru the transverse median plane of one type of boat constructed in accordance with the invention. This plane is in the midship portion of the boat; and the sectional view is toward the bow.

FIGURE 2A is a plan view, partly in section, indicating on a reduced scale a row of the casings of FIGURE 1, shown in a vulcanizing chamber.

FIGURE 2B is a detail view in section, partly broken away, of the outer two inflated casings of the row shown in FIGURE 2A, illustrating the vulcanization of the rubber casings together.

FIGURE 3 is a detail view in section thru the hull, showing the means of fastening a hatch, porthole or door to and between the inflated casings of the hull.

FIGURE 4 is a vertical detail view, in section, of an alternative structure for fastening the inflated casings of the top deck or overhang of the boat of FIGURE 1 to a vertically-stacked row of casings in the vertical part of the hull.

FIGURE 5 is a detail vertical view, in section, of an alternative structure for fastening the inflated casings of the lower deck of the boat of FIGURE 1 to a verticallystacked row of casings in the vertical part of the hull and float.

FIGURE 6 is a detail view, in vertical section, thru the lower deck of the boat of FIGURE 1, of an engine mounting in a recess within the lower deck.

FIGURE 7 is a detail view in horizontal section thru the junctions of two horizontally-arranged rows of inflated casings of the lower deck, partly broken away, illustrating an alternative means for mounting an engine and steering apparatus.

FIGURE 8 is a side elevation, partly in section, of a second form of the water vehicle.

FIGURE 9 is a plan view of the boat of FIGURE 8.

FIGURE is a vertical, sectional view, from an athwartships plane in the midship portion of the boat of FIGURES 8 and 9.

FIGURE 11 is a detail view in section from a transverse plane thru the midship portion of the boat of FIGURES 8 and 9, partly broken away, and showing an alternative construction of the lower outer part of the boat of FIG- URES 8 and 9.

FIGURE 12 is a detail view, similar to FIGURE 11, but showing adjoined parts of the hull, lower deck and float in transverse section of part of a third, arched-top form of the invention, which utilizes extruded rubber tubes.

FIGURE 13 is a detail, sectional view which illustrates a method of spacing the extruded tubes of the hull or deck of the third form of the invention.

FIGURE 14 is a detail, sectional view of an alternative assembly of the inflated tubes of FIGURE 12.

FIGURE 15 is a detail view, similar to FIGURES l1 and 12, but showing adjoined parts of the hull, lower deck and float in athwartships section, a fourth form of the invention, which also has an arched top and utilizes extruded rubber tubes.

FIGURE 16 is a plan view, partly in section, illustrating an optional method of assembly of the floats and lower deck of the boat of FIGURE 1.

FIGURE 17 is a plan view of a fifth form of the invention.

FIGURE 18 is a side elevational view of the 'boat of FIGURE 17.

FIGURE 19 is a detail view in section, partly broken away, from the plane 19-49 of FIGURE 17.

FIGURE 20 is a sectional view from plane 2020 of FIGURE 18, showing an outer, streamlining envelope around fore-and-aft arched tubes.

For clarity of illustration the sectioned rubber-andfabric tubes are shown in all figures except 12 to 14 without their fabric or cord reinforcement. They are hatched to indicate synthetic-rubber or other plastic, but ineach instance natural-rubber plastic obviously may be substituted for the indicated synthetic plastic.

FIGURES 1 to 6 show a form of the invention which utilizes inflated, doughnut-shaped casings, which may be newly made of rubber or other flexible plastic, preferably reinforced with fabric, cord or wire. In this event, the casings are of much thinner walls than those of FIGURE 1; but in this form the invention preferably utilizes tirefactory-rejected, surplus or used automobile tires, 2, of synthetic or natural rubber. If these tires are not much worn they preferably are made lighter by machining off part of their tread. The rubber thus reclaimed may be used in the rubber industry.

The boat comprises a plurality of horizontal rows, 3 and 4, and a plurality of vertical rows, 5, of such tires or casings. Each row comprises a plurality of the casings, held side-to-side and tightly together by vulcanization and by taut, tensile elements 6, which may be ropes of plastic or other fiber, wires, or small-diameter metallic rods. In this form of the invention, the casings are arranged to form a craft that preferably has a generally rectangular shape in horizontal cross section, a flat bottom, indicated by the arrow of numeral 7, and two float portions, indicated at 8, that extend the full length of the boat.

The side walls of the casings are hermetically vulcanized together; and at the end of each row, 3, 4 or 5, there is a metallic, disk-like casing holder, 10, which in combination with the vulcanized casings forms an inflatable chamber for air, or other gas which may be, for example: ammonia (which has a weight but little more than half that of air); ammonia mixed with helium, hydrogen or neon; hydrogen mixed with an inert gas such as neon or carbon dioxide; or air mixed with helium or neon. This casing holder and air chamber closure may be newly made of a light metal, such as aluminum alloy, but preferably it is a used, inspection-rejected or surplus automobile wheel of a size that fits the casings of its row. To reduce its weight its side that is toward the middle casings of the row is bored or slotted in various places, as indicated at 12. But the holders outer side, 14, is impervious to gas except thru the inner end of the inflating-gas inlet tube 16, which is fixed and hermetically sealed within a hole in the casing holder. At the other end (not shown) of each of the horizontal rows 3 and 4 there is a similar metallic holder, but, like the one at the bottom of float 8, it does not have a gas-inlet tube.

When tensile elements 6 are metal wires, cables or rods they preferably are welded to the casing holder at one end of a row, as indicated at 18. But when they are polyethylene or other fibrous ropes each is fixed at one of its ends to the eye of an eye-bolt, and the other end of the bolt is hermetically welded to the holder. The end of each tensile element that is opposite to its welded attachment is adjustable relative to the holder at that end. If the tensile element is of fiber or wire it is fastened to the eye, 20, of an eyebolt, and its nut 22 may be tightened against outer surface 14, to draw the casings more closely together in the row, against the pressure of their inflation. As indicated in FIGURE 1, at the center of each of the side rows 5 there is a metal rod, and its length within the closed air (or other gas) chamber is adjustable by its screwthreaded end and nut 24.

If automobile wheels are utilized as the metal casing holders, the tensile elements may be threaded thru three of the standard openings which have been made for holding bolts from the wheels hub. In this event the other two of the five standard holes are closed by metal plates that are welded over them. Alternatively, all five of the original openings may be closed by welding a metal plate or plates over them, and three new holes bored thru the wheels central disk, near its outer periphery, for passage of the tensile elements. Although one central tie element in each row would be satisfactory in most instances, three tensile elements, equally spaced around a circumference on the central disk, giving extra strength to the row, are preferred.

A metallic loop, 25, is welded to the top of nut 24, thru which the fibrous-plastic rope or other cable 82 is extended, for a purpose that will be later described. At the other end of each of these central tensile elements the rod is formed into another loop, 27, thru which the looped cable 82 also passes.

When the casings are economical tire-factory-rejected, used or surplus tires they may be assembled in the rows with unaltered or slightly machined shape. But preferably, and as shown in FIGURE 1, some of the casings of each row do not have the standard cross section of a common rubber tire, but instead have a considerably smaller volume of hollow space within their plastic walls. For extra strength of the vehicles lower deck and its attached pair of floats, the side walls of the two casings at each end of row 3 are of the normal tire volume and shape; but those between the end pairs have a radial extent that is a little more than half that of the standard tires side walls. When tire-inspector-rejected, surplus or used tires are utilized, these inner, smaller casings of each row preferably are formed by cutting the tires along a circumference indicated at 26. In the upper row 4, where less strength is required, preferably only the two end casings, which are mounted on metal holders, are of the standard tires shape and volume of side-wall-enclosed space.

Within the circumference 26 and the main gas chamber of upper row 4 (which preferably contains compressed air), cylindrical containers, 32, of a lighter-than-air gas or vacuums, float upward and exert a lifting effect on the row of casings and the boat. The preferred lift-providing gas is non-explosive helium, but where helium is not available or is too costly to be economically used, hydrogen, or a mixture of hydrogen and a small percentage of inert gas or of gas that does not support combustion, may be utilized. Examples of such gas that neutralizes the tendency of hydrogen to burn in air are: neon, ammonia, carbon dioxide, sulphur dioxide, freon and argon. Because the floating inner gas containers are of material that remains impermeable to gas, and their freedom to shift within the compressed gas protects them from being broken open, they may be safely filled with pure hydrogen. Moreover, when the outer gas in the inflated rows is not pure air, but instead is a gas or mixture of gases which does not support combustion, for example, air mixed with a small percentage of carbon dioxide, sulfur dioxide, ammonia or neon), pure hydrogen may be utilized as the inner, lifting gas with absolute safetyeven in the unlikely event of breakage of one of its receptacles. Both sulfur dioxide and carbon dioxide are excellent preventers of combustion. Because carbon dioxide is so efficient in this respect and is very economical it is preferred as a safety factor in the outer, inflating gas. When hydrogen is the inner gas a mixture of 85 to 90 percent of air and to percent of carbon dioxide is preferred as the inflating gas. Carbon dioxide is about one and a half times as heavy as air, but its small percentage in this mixture and the fact that the floating, lighter-than-air units fill nearly all the inflated space within the rows (leaving little space to be occupied by the inflating gas) make this slight extra weight a very small handicap in the vehicle's lifting power. Air that contains 15 percent 'of carbon dioxide is an absolute bar to combustion, but

10 percent of carbon dioxide is a good safety factor against the burning of hydrogen. In practice, the outer tubes may first be inflated with aerial mixture containing 15 to 18 percent of carbon dioxide, and thereafter, as the inflating gas slowly escapes thru the tubes, it would be replaced with pure air by the boats operator; and at rare intervals more carbon dioxide would be added at fuel or repair service stations.

But when the inner receptacles contain hydrogen mixed with a little inert gas (such as neon, nitrogen, ammonia, helium, carbon dioxide or sulfur dioxide) or contain helium or vacuums the inflating gas is preferably ordinary air. Because of the fact that hydrogen is nearly 14 and a half times less dense than air this lightest of substances is an excellent gas for providing the crafts aerostatic lift, and in the present invention its safety is insured by one or more of the above-described methods.

As indicated above, the inner containers are of sufficient number and total volume to occupy nearly all the space within the circumference 26, but there is enough total clearance within the row of rubber casings for it to yield, as from the pounding of a wave, without appreciably buckling the lighter-than-air units. Their very thin walls, of a material that is impermeable to gas, may be of thin metal-for example, aluminum or magnesium alloy, extremely thin pure iron, steel or copper. Optionally, they may be of glass, plastic that is dense and substantially impermeable to gas, or titanium. When they are of flexible metal or plastic their gas preferably will be of a pressure greater than that of the atmosphereequal or nearly equal to that of the air within the inflated casing row. When their material is glass, strong and rigid plastic, or titaniumand therefore able to withstand considerable compression-their light-weight gas may be at atmospheric or lower pressure; or, optionally, they may not be filled with any gas at all, but may contain vacuums.

On some or all of the containers buffer rings 34 of flexible, porous plastic (or equivalent fabric) may be placed. These elements, preferably of foam rubber, prevent noise and shock to the receptacle walls when they float together.

An optional type of the lighter-than-air units is shown within horizontal row 3 and vertical row 5 of the casings. This is a cylindrical housing 36 which has a tubular, openended space at its centerwithin cylindrical wall 38. Tensile elements 6 extend thru these hollow spaces.

Within them porous-rubber rings 40 optionally may be cemented in place as buffers.

For ease of illustration the cylinders of the lighter-thanair units have been shown as having flat ends. But in practice these ends preferably will be spherical. In lieu of the cylinders, numerous hollow globes, of the type illustrated in FIGURES 8, 10 to 12 and 17 to 19, may be used.

FABRICATION OF THE ROWS The rows of casings are separately made. They are vulcanized together by any appropriate, known rubber vulcanizing or molding method.

One way of forming a row is indicated in FIGURES 2A and 2B. The box or chest shown in FIGURE 2A is made of metal, preferably with an access opening, 42, at one or each end, thru which a workman may extend a socket wrench for adjusting the nuts at the ends of the tensile elements. This opening is closable by cover 44. The chamber has a top lid, 46', with hinges 48, and hookand-eye or other clamping fasteners 50 for holding the lid tightly against the boxs rim during vulcanization. This lid supports on its lower surface, depending from its two long-edge borders, the pair of heating coils indicated at 52. When the casings are assembled in the chamber and the lid is closed there is a clearance or heating space between the coils and the casing perimeters.

The tensile elements 6 are threaded thru the hollow center of each casing as it is put in place in the chamber. Since the casings fit rather closely in the box they are held in alignment by its side walls. Before each casing is installed in the autoclave its bulging sidewalls preferably are roughened and coated with putty-like, sulfurcontaining, unvulcanized rubber compound; so that between each two casings the layers of compound merge into a glutinous annulus, indicated on a more enlarged scale in FIGURE 2B at 54. When all the casings are installed except the one (or pair, as shown at 55) at an end of the autoclave, the lighter-than-air unit (or plurality of units) is inserted thru opening 42. Then the end, small-bore casing (or pair of casings) 55 is installed and the nuts 011 the ends of tensile elements 6 are moderately tighteneduntil the sidewalls of the casings are slightly collapsed against each other in sealing relationship. The tensile-element nuts are temporarily sealed with glue against the metal holder of the end casing 55; and the tensile-element holes in the casing holder at the other end of the autoclave previously have been sealed by welding. Cover 44 is now screwed over opening 42; compressed air is admitted thru the air-inlet valve; steam is supplied to the autoclave thru pipe 57; and electric current is conducted to the heating elements 48 thru wires 56 and connections 58. The compressed air within the casings holds their sidewalls tightly sealed together while they are being vulcanized.

After the heating period is over the vulcanized row is removed from the chamber, and the tensile-element nuts are welded to the adjacent metal holder. The inflated row is then tested under water, and if there is a leak it is stopped by further vulcanization. This may be done with the aid of a heated clamp whose support encircles the row.

An alternative, cold-vulcanizing method of fastening the casings of a row together comprises the following steps: coat the roughened sidewalls of the casings with rubber cement; place them successively in a chamber which is similar to the above-described box but which does not inclose heating elements; place the lighter-than-air units within the casings; hermetically seal and inflate the interior of the casings in the above-described manner; close the box; and admit the vapor of sulfur chloride to the chamber thru a pipe similar to 57.

A third method is the following: (1) glue the roughened sidewalls together while they are under pressure from the tie elements and nuts; (2) weld the nuts and heads of the tensile elements to the metal holders; (3) coat the V- shaped recesses between the casings with vulcanizing compound or cement; (4) wrap a strip of fabric-backed, glutinous rubber of V-shape in cross section tightly around the row at each of said recesses and fasten the fabric ends tightly together; inflate the interior of the casings by admitting compressed air thru the inlet valve; (6) place the unfinished row in the above-described, heated vulcanizing chamber; (7) close the chamber; and (8) supply electric current to the heating elements.

A fourth method of making a casing row is to stack the casings in a vertical rack that comprises four uprights placed at the corners of a square and held together by cross pieces fastened to their outer surfaces. These uprights are spaced and shaped to rather closely confine the circumferences of the stacked casings in vertical alignment. The heads of the tensile elements 6 are welded to the bottom metal holder before it is placed in the bottom of the rack, with the tensile elements projecting upwardly thru its casing. The bulges of the sidewalls of each casing are roughened and coated with rubber or other plastic cement; and shortly thereafter it is stacked on the preceding casing in the rack, with the tensile elements threaded thru its hollow space. Installation of the lighterthan-air units and the heavier outer casings at the top of the rack completes the assembly; and the tensile elements are quickly tightened. The whole assembly has been quickly effected, so that the glue is not dried on the contacting sidewalls until they are forced firmly together (but not to the point of appreciable collapsing) by the tie elements and nuts.

These nuts are now sealingly welded about the holes thru the upper metal holder. And after the cement is hardened, a V-shaped strip of fabric (or a thick fibrous cord), coated with plastic rubber of the type that vul canizes Without the use of heat is wrapped around each pair of casings, in the V-shaped annular recess of their intersection. This fibrous element is tightened (by pulling or twisting it); its ends are tied, pinned or stapled; and then the hollow space within the row is inflated with air, thus pacing substantial pressure on the casing sidewalls, against the rubber-coated fibrous element, until its compound is vulcanized.

Vertical row 5 is made in the general manner set forth above, but for extra strength this row has two pairs of metal holders at its top and center. The pair at the center are strongly fastened together by means of a short cylinder, 60, of metal (steel or aluminum alloy, depending on which metal has been used in the wheel). Thru one side of the cylinder a hole is bored; in this bolt 62 is inserted, and its head is welded to the inside of the cylinder. Then the cylinder is held between the two wheels and hermetically welded to their rims. If desired, all parts of cylinder 6% except the portion that is bored may be of sheet metal, but the bored portion is thick and strong.

The upper pair of metal casing holders may be fastended together in the same manner, but they are shown in FIGURE 1 as being joined by an alternative method. Four metal tie elements, equidistantly spaced around the wheels, are welded to their central disks. Three of these are narrow bars or rods, of which only one, 65, is visible in FIGURE 1. The fourth is bar 65' which is bored to provide a hole that registers with a similar hole in bar 66, that is also welded to the two wheels. In these two holes turnbuckle bolt 68 is fixed against its turning, for example by welding it. to bar 65'. This bolt, as well as bolt 62, preferably lies in shallow grooves cut in the rubber of the sidewalls of the two casings between which the bolt passes. The casings of row 5 are fastened together by tensile elements and vulcanization in the manner of those of row 3.

Preferably the metal-centered casings of the upper part of row 5 and in row 4 house doughnut-shaped containers 67 of helium, other light gas or vacuums. Optionally, these containers may be hollow spheres, arranged in a circle.

The resulting inflated tubular articles 3, 4 and 5 may be used in various ways in the manufacture of boats or other 8 vehicles-for example, the boat of FIGURES l and 3 to 7-, which has been partially described above.

These and the other inflated tubes of this invention are stiffened and strengthened by inflation at a pressure above that of the atmospherepreferably in the range of eighteen to thirty-five pounds per square inch. The pressure chosen for each tube may depend on its location. For example, Where an inflated receptacle forms part of the strength-providing framework of a float or of a deck the pressure of its compressed gas preferably is in the range of twenty-five to thirty-five pounds per square inch. But where a tube is not subjected to the force of waves or of transported loads or peoples steps, the pressure of its inflating gas preferably lies in the range of eighteen to twenty-five pounds per square inch.

The craft of this invention thus has much more rigidity and strength than the currently known aviators inflated life-raft. And yet, unlike presently utilized boats of more rigid material, it can yield under the severest shocks a large multiplicity of times, and each time return Without damage to its former configuration.

In any of the forms of the present invention, a currently preferred type of an inflated tube that is part of a deck or of a floating portion comprises compressed inflating gas at a pressure of twenty-eight to thirty pound-s per square inch; and the preferred form of the other tubes of the craft comprises inflating gas at a pressure of eighteen to twenty pounds per square inch. For the float and lower deck portions of the boat this gas preferably comprises air; and for the upper tubes (those above the center of gravity of the craft) it preferably comprises ammonia. If the lighter-than-air units of airinflated tubes contain hydrogen the compressed air adjacent to these units preferably is mixed with a small percentage of carbon dioxide or ammonia. Such hydrogen-containing units in receptacles that are inflated with ammonia are thus surrounded by a non-combustible gas. Ammonia is not only non-combustible (in the absence of a special catalyst, such as platinum gauze), but as a tube-inflating gas it also has the advantages of being lighter-than-air and readily and economically procured.

ASSEMBLY OF THE ROWS IN THE VEHICLE OF FIGURES 1 TO 7 In assembling the horizontal and vertical rows of casings, a plurality of pedestal-s, 69, are utilized. For a relatively small cabin cruiser or boat four of these are arranged along the lines of a horizontal rectangle which are within and parallel to the planned vertical sides of the boat. If the craft is relatively long other pedestals may be placed in these lines. Planks 70, fixed to the tops of the pedestals, extend the length of the craft, one board (or row of boards) being adjacent to the inner line of the pair of planned floats. Alternatively, the pedestals may be in the form of metallic jack stands of conventional design, and wooden or metallic elements '70 may be bolted to the top plates of these stands.

The first step in the assembly of the rows into a boat is the placing of a rubber coated or impregnated fabric of nylon, fiberglass or the like across the parallel planks 7t stretching it until it is very taut, and thumbtacking or otherwise temporarily fastening it to the edges 71 of the parallel planks. Its free folds on all sides (long enough to finally cover the outer surfaces of the boat except the ports and forward windshield) are then tucked out of the way, between the pedestals.

A horizontal row 3 is now coated with waterproof cement on the bottom curves of its casings and laid across bars 70, in glue on the rubberized fabric. Then a vertical row 5 is abutted against it, and turnbuckle 72 is screwed on bolts 62 and 74 (each being hermetically welded to the adjacent casing holder) until the wet-glue-coated sidewalls of the contacting casings of the two rows are slightly flattened, against the resilient pressure of the air inside the casings and rows. And a second row is cemented and fastened to the other end of row 3. Next, another row 3 is laid in glue on the rubberimpregnated fabric, jammed (in glue) against previously laid row 3, and cemented and fastened to a pair of vertical rows 5. The contacting portions of each pair of the vertical rows also are glued together, preferably with fast-drying waterproof cement and while the rows are clamped together by a clamp that spans two of the metallic eyes 76 that are welded to the upper casing holders. Since the bottoms of rows 5 rest on the floor it is unnecessary to clamp their lower ends together; but if desired this may be done by temporarily fastening a clamp around bar 70 adjacent to the last-laid row 3, and wedging the row (and thus also row 5) between this clamp and the other row or rows 3, against a stop that has been located on the free side of the first-laid row 3.

After all the sets of rows 3 and 5 are assembled except the last set at the bow and the last set at the stern, other pedestals and boards (of the type of 69 and 70) are placed on the ends of rows 3; and on top of these boards the upper-deck rows 4 are successively laid and tightly fastened to side rows 5 by screwing turnbuckles 78 on the ends of bolts 68 and 80. Then the upper pedestals and boards are removed from the inside space thru an upper-deck hatchway or thru a side door, built in the manner indicated in FIGURE 3.

Preferably, this boat has straight, parallel vertical sides, is flat on the under sides of rows 3 and the bottoms of float portions 8, but is streamlined on the upper surface of the top deck that comprises rows 4 and the tops of rows 5. To achieve this streamlining the pair of vertical rows 5 at the stern are relatively short, allowing for a space between top row 4 and lower row 3 of a distance equal to the outer diameter of one of the casings. This arrangement provides for three vertically aligned rows of horizontal casings at the extreme stern of the cabin, so that the middle row can be interrupted for the interposition of a glass-closed port there, of the type shown in FIGURE 3 and later to be described, for rearward vision from the cabin. Forward from this after, cabin-closing set of three rows the heights of succeeding rows 5 are stairstepped upward until the space between rows 3 and 4 is about seven feet in height. From this point until the streamlining of the bow begins the rows 5 are of equal height. Thereafter, they are stairstepped downwardly, in chords of a streamlined curve, until the height of said space is approximately equal to two exterior, major diameters of the row-3 casings, sufficient for the helmsman and/or passengers to sit there and look out of the bow thru a transparent windshield. At the extreme bow the last pair of vertical rows therefore are joined by four horizontal rows 3, and the middle two of these horizontal rows are interrupted (in the manner indicated in FIGURE 3) by insertion of a relatively long glass or plastic window that is short in height.

After the outlines of the boat are thus formed, polyethylene or metal cables 82, which have been successively threaded thru bottom loops 27 and eyes 84 as rows 5 were placed in the assembly, are now looped all the way around rows 5, by threading them thru eyes 76 at the top deck. The ends of each cable are fixed to the two bolts of a turnbuckle; and the turnbuckles are tightened until the cables are very taut, against the resilience of the inflated casings over which they loop. For further securing of the sets of rows together, flexible belts 86, of rubber coated and impregnated cords, fabric or wire, are stretched tautly, by means of turnbuckles at their joined ends, over each vulcanized junction between adjacent horizontal-row casings. Because of cables 82, reinforced rubber belts 86, tensile elements 6, and bolts 62 and 68, the boat has great strength against the buckling force of waves.

The craft may now be completed by two operations: (1) appropriately cutting or doubling the parts of the rubber-impregnated fabric which have been tucked under the bars during the assembly of the rows, so that they have the proper extent for coverage of the lower, top and side surfaces of the boat; and stretching these parts tightly over the freshly-glued, rubber surfaces of the outer parts of the casings; and (2) pouring an adhesive, light-weight, porous and resilient material into the interstices between the casings, so that the boats lower deck, upper deck and other outer surfaces are smoothly continuous. This porous substance may be a mixture of cork and paint, but preferably it is foam rubber or other porous, resilient plastic.

The rubber-coated fabric is at first glued only to the side, bottom and end surfaces of the assembled vertical rows 5. At the tops of these rows it is tautly fastened to lifeline-holding rods 88, which are welded to certain ones of the top metal holders of the casings of rows 5. This attachment of the fabric to rods 88 (and optionally to a narrow plank or other bar, temporarily fastened to rods 88) is at a level that is slightly above the top level of the casings. Into the quasi pan thus formed and between the curving sides of the joined casings and rows,

the foamed rubber or other flexible plastic is poured. This foam fills the voids between the outer surfaces of all the casings.

Then the nearly completed boat is removed from the bars 70 and placed within a heating chamber where the foam is gelled and vulcanized under conditions which prevent the water in the foam from evaporating. After the vulcanization the upper surface of the foam, on the top deck, is covered with rubber cement or other glue, and the rubber-impregnated fabric is folded over the deck and pressed into the cement. Preferably, another ply of the waterproof fabric is then cemented over the joints of the first ply.

FIGURE 3 illustrates a method of attaching a hatch, door, window, port or propeller shaft housing to the intermediate casings of a row. The specific support shown is a frame, 90, of wood (or optional metal) for a hatchway thru the top deck of the boat. This frame may be similarly placed in the vertical rows 5 to provide a glasscontaining port, made longer for a door thru the vertical rows 5 or a window in the bow or stern casings, or made shorter to provide a propeller shaft housing that provides an opening thru the lower-deck or stem casings. But in any event its width remains equal to the outer diameter of the row of casings which is interrupted for its placement.

A tight seal between the casings and frame is obtained by making its periphery slightly larger than the opening between the casings when they are fully inflated, coating the surfaces of the casings and frame that are to be in contact with glue, deflating these casings, installing the frame, and then re-infiating the casings against the frame.

Each of the metal holders of casings 92 and 94 has welded to its inner periphery a pair of bars or other metal elements 91, which have eyes 96. Thru these eyes two of the tensile elements 6 extend; and they are further threaded thru a second pair of eyes on bolts 98, and then are terminated in a knot 100, or other means for their attachment to the bolts. By means of the nuts on these bolts, they are drawn toward the frame opening, thus pulling taut the attached tensile elements. On each side of the frame the central tensile element is directly attached to the eye of bolt 104, without need of its being angled by an intermediate lug and eye.

FIGURES 4 and 5 show alternative methods of attachment of horizontal rows 3 and 4 to vertical rows 5. In FIGURE 4, one end of rod 106 is welded at 108 to an end casing holder of horizontal rod 4, and the other end is screwthreaded to fit nut 112. This rod is curved upward and around the top casing of row 5, and in assembly of the two rows the threaded end of the rod is put thru an eye in lug 110, which is welded to the top casing holder of row 5. Between the contacting surfaces of the casings of rows 4 and 5, rubber cement or the like is placed, and these surfaces are then forced together, against their inflation, by screwing nut 112 against lug 110 until the casings are slightly collapsed.

The structure of FIGURE 5 is shown at a point in its manufacture just prior to the pouring of foam rubber into the interstices between the casings. Rod 114 is welded to the outer surface of an end casing holder of horizontal row 3, and rod 116 is welded to the holder of an intermediate casing of row 5. Rod 116 is sealed between two of the casings by means of rubber vulcanizing strip 118-or, optionally, the rod is cemented on grooves in the casing sidewalls. In assembling this type of joint between rows 3 and 5, a workman extends a too downward between the circumferences of a pair of casings of row 5, and thus is able to rotate turnbuckle 120. It is thus screwed on rods 114 and 116 until the inflated casings of rows 3 and 5 are tightly clamped together, against their resilience.

A means for mounting an engine near the stern, in a space between a pair of metal-centered casings of the bottom row 3, is shown in FIGURE 6. The housing of engine 122 maybe non-rotary, but as shown it has a power shaft tube 124 that is journaled in bearings 126. The upper end of the engine casing is fixed to the vertical shaft of the steering mechanism, which comprises tiller 130 (or an equivalent gear of a steering apparatus that is controlled from the bow by electrical or other linkage). The housing and elements 124 and 130 are journalled in bearings 126 and 128. The boat may thus be steered by pivoting the motor, tube 124, and propeller shaft 132. This shaft is driven from a bevel gear at the base of the engine shaft that extends downward thru tube 124.

An exhaust manifold, 134, is rotatably and sealingly mounted on the engine casing, and is fixed to exhaust pipe 136. This pipe extends upward and thru an interstice between four of the casings of upper row 4; it is sealingly bonded there to the foam rubber in said interstice. Optionally, these exhaust elements may be eliminated, and the exhaust sent, with engine-cooling water, thru the power-shaftsupporting tube and thus out of the boat, in a manner that is well-known in the outboard-motor art.

Alternative means for mounting the engine and steering apparatus are shown in FIGURE 7. The motor housing is mounted on the foam rubber of the lower deck, and the engine shaft 138 extends downward thru the foam rubber of an interstice between four casings of row 3. This shaft is journalled in bearings that are supported in tube 140. At its lower end the tube is connected with a housing for a gear and propeller shaft, of the type that is indicated in FIGURE 6 and is currently well known in outboard-motor boats. Thru another interstice between casings, directly aft of engine shaft 138, there is another tube, 142, in which a rudder shaft, 144, is journaled by means of a sleeve bearing and seal. Preferably, the engine shaft and its tube are mounted between four full-size casings, as shown. If further stiffening of this part of the boat is desired, these four casings may be mounted on metal holders.

FIGURES 8 to 11 illustrate a form of the invention in which the floats comprise used, surplus or tire-inspectionrejected tires, or equivalent rubber-and-fabric tubes, arranged in rows that have fore-and-aft axes. Although only one fore-and-aft row of casings is here shown for each float, preferably there are three or four such rows, as indicated in FIGURES and 11. All the casings of a float are assembled and glued, or vulcanized, in airtight relation, with their central tensile elements holding the inflated casings tightly together, against their resilient force. Then over the screwthreaded ends of the tensileelement bolts, that project outward from the forward casing holder, the after holes in the hollow, metallic float core shown in FIGURE 8 are fitted. At this time the corcs top plate 146 (or alternatively the cover of a handhole in the plate) is removed from the core, so that a workman can insert a tool within the hollow space and screw nuts on the tensile-element bolt ends until the core is tightly clamped against the inflation-resilience of the casings. After this is done, sealed thin-metal or plastic balloons 148 of helium or other light gas are put in the hollow space, and then the cover 146 is sealingly fastened, by cementing, welding or brazing, to the sides of the core. Portion 150 of the float nose is foam rubber or other .porous plastic material which is formed in situ, within an envelope of waterproofed fabric, at the same time that the other parts of the boats outer surface are made.

The upper deck has side rails 152, made of small-diameter, aluminum-alloy rods. They are joined to the inclined handrails 153 of the after ramp, leading from the lower to the upper deck, and to the outer handrails 154 of the two forward ramps that extend between the upper deck and the forward portion of the lower deck. The after ramp has two side passageways, comprising rough step portions 156, formed on the waterproofed envelope by means of coatings of glued asbestos fiber, fiberglass, cinders, or the like. The Forward pair of passages are also flanked by inner handrails 158; and their surfaces are coated with rough-tread substances 160.

In the lower middle portion of the after ramp there is a hinged hatch or door, 162, which has a pane, 164, of glass or transparent plastic. Other access to the interior of the craft is by way of hinged hatch 166, which preferably has a translucent skylight, 167, at its center.

Two optional types of construction of the midship portion of the craft of FIGURES 8 and 9 are shown in FIGURES 10 and 11. The framework of the upper part of the boat comprises bars of light-weight Wood or metal-preferably of balsa, cypress, cedar or tupelo woodsecurely fastened together and braced in a generally triangular fashion. In FIGURE 10 the cross-sectional plane cuts thru braces 168 and 170. Bars 168 are bolted or nailed to inclined bars 172 and horizontal bars 174. These boards 172 and 174 are spliced and bolted together at the upper ends of 172, so that braces 168 may be bolted tightly against both 172 and 174. Bars 172 are also bolted to upright braces 170, and braces are bolted to deck beams 176. The lower ends of these braces are beveled so that they fit between the upper pairs of the float casings. Bars 172 are also bolted to beams 176. Lifeline posts 178 are nailed or bolted on top of braces 168, and also are securely fastened to the sides of bars 172. Thus a cross section of the framework of the craft is in the shape of a truncated pyramid, and is securely braced in generally triangular fashion.

Each float comprises four rows of large inflated casings, that are clamped together by cables 180, and a smaller, central, inflated tube, 181, of rubber-and-fabric. The bolts that tighten lower cables 180 against the hollow nose and stern cores of the floats are also Welded or otherwise fixed to the lower ends of cables 182. These cables extend upward thru the nose cores of the floats, thru holes in covers 146 (FIGURE 8), and then loop backward thru holes in deck beams 176 and thru the hollow cores in the after streamlined portions of the floats. They are tightened by means of turnbuckles that join them to the after bolts on cables 180. The floats contain lighter-than-air units 183.

The planking 184 of the overhang is nailed or screwed to inclined bars 172, and the deck planking 186 is similarly fastened to beams 1'76. Glued to the upper surfaces of bars 172, the lower surfaces of beams 176, and around the float casings, there is a rubberized, waterproof fabric, 188. And between this fabric, bars 172, beams 176, planking 184 and 186, and the float-casing peripheries there is a light-weight, resilient filler of poured and vulcanized foam rubber or other plastic, 190. Within this insulating, porous filler there are located many thin-walled containers 192 of helium, hydrogen, vacuums 13 or the like. These spherical, cylindrical or egg-shaped vessels have walls of a dense material, which may comprise aluminum, magnesium, iron, glass or plastic. Also such curved-surface, lighter-than-air units 194 float above plywood overhang 196, and against the waterproof fabric that is at the base of the foam rubber between braces 168. Numeral 198 indicates planking or plywood that is parallel to the fore-and-aft axis of the boat and is nailed or screwed to bars 174, as well as 172 and 168.

Within the cabin a light-weight seat is made of curvedsurface, preferably cylindrical lighter-than-air units, covered with foam rubber or other resilient porous plastic. Preferably they comprise thin-Walled vessels of metal, dense plastic or strong glass, 2011, that contain helium, hydrogen or vacuums. And a light-Weight table is provided that comprises such lighter-than-air units, 204, and hollow, thin-metal or waterproofed-fabric legs, 206, inflated with helium or other lighter-than-air gas at a pressure within the range of twenty-five to thirty-five pounds per square inch.

On an enlarged scale, FIGURE 11 illustrates an alternative type of float in the process of its construction. Here only three rows of casings are utilized. The lower casings are of smaller diameter than the upper rows, thus providing a generally circular float contour. Hollow core 208, which preferably is of inflated rubber-andfabric or other reinforced plastic but optionally may be a metallic helium-containing element, is wedged between the upper pair of rows. The rubber part of this hollow core preferably is an extrusion; it extends the length of the hull and beyond to the hollow core elements of the streamlined float nose and stern. Elements 210 and 212 are lighter-than-air units, imbedded in the foam rubber. Their walls may be of glass, aluminum, magnesium, magnalium, aluminum-titanium alloy, plastic, or other material that is impervious to gas. In this construction they preferably contain hydrogen, a plentiful and economical gas. Sealed hollow spheres or cylinders 214, in the floats and therefore subject to more wave-buffeting than the deck units, also contain a lighter-than-air gas, which in this instance preferably is helium or hydrogen mixed with inert gas.

FIGURES 12 to 14 illustrate a form of the invention which utilizes extruded rubber tubes and in which the crafts top is arched in transverse cross section. In FIG- URE 12 the major portions of the floats are separately made from the remainder of the boat. They may comprise corrugated rows of rubber tire casings (assembled as set forth above), but as shown in this figure they utilize corrugated rubber-and-fabric tubes that do not have tensile elements in their hollow spaces. In lieu of the rubber corrugations, which provide spaces thru which foam rubber may be poured, ropes or other cables or bands may be wrapped around cylindrical rubber tubes. One method of making these corrugated tubular elements, using economical rubber extrusions (which may be square in cross section but preferably are cylindrical), is the following:

(1) Placing within each hollow extruded tube spherical or cylindrical lighter-than-air units (this may be done by extruding the tube over the temporarily stationary containers in one operation);

(2) Hermetically closing the open ends of the tube by bonding rubber disks to them;

(3) Placing the closed tube within a fabric sack (which preferably is of nylon and has a slightly smaller diameter than that of the rubber tube), and sewing a piece of fabric over the sacks opening thru which the tube has been inserted;

(4) Inflating the resulting composite tube;

(5) Forcing over each end of the tube a band or ring that is slightly smaller in diameter than the tube and may be of resilient, vulcanized rubber, uncured rubber compound, fabric or other fibrous material, hard porous plastic, or metal; and

(6) Vulcanizing the inflated composite tube in an autoclave or by cold vulcanization.

Alternatively and optionally, the tubular element may be formed by:

(1) Tightly wrapping a series of longitudinally-spaced spherical or cylindrical lighter-than-air units in a thin sheet of foam rubber;

(2) Wrapping around the foam-rubber-enveloped containers (serving as a mandrel) a sheet of unvulcanized rubber;

(3) Joining the meeting, freshly-cut edges of the rubber, by applying rubber cement or naphtha to them;

(4) Bonding disks of pure rubber to the ends of the tube, thus closing it;

(5) Sacking the pure rubber container thus formed in at least one cylindrical envelope, wrapped closely around the rubber, sewing a piece of fabric over and around the mouth of the envelope or sack, and pressing the fabric of the envelope into the rubber (this may be done by means of a clamp comprising two hinged halfcylinders of metal and/ or by small rollers-for example, of the wrapping machinery);

(6) Placing a ring of cured or unvulcanized rubber, plastic or fibrous material over each end of the tubular article;

(7) Vulcanizing the rubber in an autoclave or by cold vulcanization;

(8) Forming an air hole thru the rubber and fabric of the cylinder, extending to a hollow space adjacent a lighter-than-air unit; and

(9) Forcing compressed air thru said hole, thus expanding the envelope of denser rubber and fabric away from the foam-rubber-enveloped lighter-than-air units, so that they are surrounded by a cushion of air under pressure.

A third way of making these corrugated tubular elements is to form them integrally in a corrugatedly cylindrical mold, wrap each of them in a long strip of narrow fabric, inflate it after lighter-than-air units have been inserted in its hollow space, and then vulcanize it in an autoclave or by cold vulcanization.

The article that results from each of these methods has annular portions or rings that, as indicated at 215, stand out in ridges from the small-diameter portion of the tubes periphery. As in the case of assembled tires or tire-like elements, these ridges or corrugations provide channels between them for the foam rubber as it is poured into the lower parts of an enveloping skin of waterproofed fabric.

In FIGURE 12, the upper two annularly-ridged tubes of each of the floats are clamped and glued tightly against a composite bar of boards or plywood, 216. Optionally, it is a single piece of light-weight wood or a hollow element of aluminum alloy or magnalium. This bar extends thru most of the floats length-that is, between its streamlined nose and stern portions. Against it the annularly-ridged tubes are clamped by means of metal or plastic cables or belts, 21S, tightened by a turnbuckle or buckle of the type shown in FIGURE 16; and then the tubes are inflated thru an air valve. Each of these tubes contains lighter-than-air spheres or cylinders, 220. On the top surface of the outer tube of each of the pair of floats there is bonded a long bar, 222; and to it at spaced intervals lifeline posts 224 are bolted.

In this nearly finished state the floats are brought to the pedestals 226 and boat-supporting bar 228, and lifted to fit against the ends of tubes 230, which previously have been laid in alignment on and glued to waterproofed plastic fabric 232. This outer skin of the boat is stretched tautly across the pair of bars 228. Tensile elements 233 are between lower curved surfaces of tubes 230; they are tightened, and draw together bars 216, by means of eyebolts that extend thru the bars. After the floats and tubes 230 are thus assembled the outer parts of skin 232 are Wrapped around the float tubes and per- 15 manently fixed to the tops of bars 222. These bars are drawn together slightly, against the resistance of their bond to the float tubes, by plastic or metal cables 234.

Steamed plywood 236, bent into an arch, is now glued or otherwise "fastened between the inner, upper sides of the two bars 216. Then over this arch rubber tubes 238 are laid, with each of the nuts on the ends of tensile elements 233 lying within the V-shaped space between adjacent tubes. They are fastened to bar 216 by metal or fabric straps 239. Rectangular or square ports of the general type shown in FIGURE 3 are mounted in holes cut in the plywood arch; they are fastened to the plywood and bonded to the closed ends of shorter tubes 238shortened to provide space for the openings. The top of the cabin slopes gently downward toward the bow, and less steeply, in streamlined contour, toward the stern; and the whole width of the bow and the stern may be occupied by framed glass or clear plastic.

Within the tubes 238 there is a series of spherical lighter-than-air units of the type described above, indicated in FIGURE 12 at 240. Optionally, these containers may be round-ended cylinders. The series may be in the form of a chain, the containers being loosely linked by a thin pad of foam rubber or light-weight cotton, laid on and glued to the lighter-than-air units, or by a plurality of pieces of foam rubber of the type shown at 242. Within tubes 230 there are other lighter-than-air units 244, the ends of which are glued to foam rubber elements 242. Preferably, and as generally indicated in FIGURE 10, there are also containers of lighter-than-air gas (or vacuums) that float upward against the upper, inner surface of the plywood arch, these units being connected by strips of foam rubber.

Tubes 230 are now inflated thru valves 246 to a pressure above that of the surrounding atmosphere; and tubes 238 for the time being are only lightly inflated by air or other economical, non-explosive gas supplied thru valves 248. A sheet of waterproofed fabric, 250, is laid on liquid-glue-coated upper surfaces of tubes 238, and its ends are fastened somewhat tautly to cables 234, as by hooks that go under the stretched cables. More air is now forced into tubes 238, and the additional inflation further tightens fabric 250. Preferably this is done before the glue between elements 250 and 238 is set.

The next step in the fabrication of this form of the boat is the pouring of foam rubber or other resilient plastic into the interstices between tubes 230 and into spaces 252 between the float tubes, the downward-flowing plastic being stopped by the lower fabric sheet, 232. To form side passageways or decks, outside the boats cabin, the foamed plastic rises over cables 234 to the top level of bars 222, and of the associated, short bars athwart the forward and after ends of the passageways. And the deck inside the cabin is formed by foam rubber that rises to a level slightly above tubes 230.

The final step in this fabrication is the vulcanization of the rubber in an autoclave or by cold vulcanization.

FIGURE 13 illustrates an optional method of assembling the extruded tubes of this form of the invention. Extruded tubes 254 having smooth, cylindrical walls, house freely floating lighter-than-air units 256. These containers have walls of glass, plastic or metal that are substantially impermeable to gas. In fabrication, the open ends of the hollow extrusions have been closed by bonded disks, and the tubes were sacked on all sides in fabric, 258, and were vulcanized and inflated, thus airforcing the rubber of 254 away from the talc-coated lighter-than-air units. In assembly, these tubular articles are bound together by a cable or belt, 266, of polyethylene or the like, which is glued and wrapped alternately over and under each end of the lightly-inflated parallel tubular elements, and then back on the other sides of the elements-again over and under the tube ends-so that the result is that the cable or belt is looped and glued all around the tubular elements.

The ends of the cable are fastened together, and the tubes are further inflated. Thus these elements are tied together in assembly and at the same time arcuate ridges are formed, spacing apart the major portions of the tubes, to allow downward flow of foam rubber in making the craft.

FIGURE 14 shows an alternative, optional method of assembly of the extruded tubes of this form of the invention. The unvulcanized tubes 2541, housing lighterthan-air units, are fastened together in spaced relation by sewing them between two layers of fabric, 262 and 264, by seams 266. After vulcanization the rubber is inflated, and thus forced slightly into the pores of the fabric and away from the talc-coated lighter-than-air units, permitting the spheres or cylinders to float freely within the tubes. No foam rubber is necessary. In final assembly, for example on the plywood arch 236 of FIG- URE 12, the lightly-inflated tubular material is bent over the rigid form, and preferably glued to it. Then the top layer 254 of fabric is stretched over and glued to the top curves of the tubular material; and the tubes are further inflated, making the outer skin taut and smoothly continuous. When no rigid cabin form is used (as in FIGURE 15) there is also an inner layer of fabric, 268, glued to the ridges of the tubular material.

The form of the invention shown in FIGURE 15 is made almost entirely of rubber, fabric and lighter-thanair units. The rubber tubes 276 are extmded in longitudinally arcuate form from correspondingly curved dies of the extruder and assembled over the lighter-than-air units by one of the above-described methods. They are lightly inflated, and their outer layer of fabric, 250, is sewed and/or glued at 272 to a longitudinal fold in the fabric sheath, 274, of the float. Hole 276 optionally may serve for flow-communication between each upright, arched tube and its attached horizontal tube 277 of the deck.

The float in this form is made without the necessity of pouring foam rubber into the interstices between its inflated tubes. Hollow rubber-and-fabric tubes 278 are pressure-expanded on and against inner curved-surface lightenthan-air units 230, and within and against a partly cylindrical waterproof fabric envelope or sack 274. The top of this envelope is held in a plane by the inflation of deck tubes 277 and by the flat top of inflated rubber element 284. This element is preferably a hollow extrusion with its ends closed by bonded pieces of rubber sheet. Inflated rubber elements 286 are similarly made, but these have curved outer portions 288, which are airexpanded against the arcuate outer envelope 274. The tubes 27 8 are flow-connected by air holes to the inside of central inflated element 290, made by closing the ends of a hollow extrusion. This element, as well as extrusions 284 and 286, optionally may be of aluminum alloy; but preferably they are of rubber. The nose and stern parts of the float may be of the type shown in FIGURE 8.

The lighter-than-air units may have containers of metal or dense plastic, but as shown in FIGURE 15 they are of glass, buffered by rubber. When the containers are cylinders this foam rubber is limited to two narrow rings 289 for each cylinder, but when spheres are used they are sheathed partially or entirely in a thin coating of the resilient, foamed plastic.

FIGURE 16 shows an optional method of assembly of the rows of inflated casings of the form of the invention shown in FIGURE 1. First, the lower-deck rows are assembled in form 288, which comprises planks or metal bars 290. These elements may be hinged, and at least two of them are fastened together to form a rectangle by means of bolts or hooks and eyes. At each corner of this form there is a vertical bar, 292, of wood or metal, fixed to a horizontal bar 290; and there are four other vertical bars, 294, two on the inner side of each planned float. To the front of each of these elements 292 and 294 there is bolted o-r screwed a float nose mold, 296, of thin metal or strong plastic. Preferably, the bottom of this mold, as shown in FIGURE 16, is a flat plate, 297, and its upper part is cunved -to form a streamlined contour, 298. (The deck and float rows of casings are here shown upside-down-in a better position for making the flat-topped floats.) There is a similar mold or form at the after end (not shown) of each of the planned floats. Also aflixed to each of the intermediate posts 294 there is another bar, 300; and fastened between each pair of longitudinally-aligned bars 292 there is another bar, 302. Bars 300 are not fastened in place until after the inflated lower deck rows are between form bars 290. The casings 304 of each deck row are held together by tensile elements 6 (FIGURE 1), and the rows are securely fastened together by taut straps, belts or cords 306. These cables may be tightened by means of buckles 307 or turnbuckles, 308.

After the deck rows of casings are thus in place and strapped together, and bars 300 are erected over them, the float rows of casings 310 and 312 are laid across the deck rows. The forward casings 312 and the similar, streamline-forming after casings (not shown) are smaller than the intermediate casings 310. After these float rows are assembled and tightly strapped by tensile elements 314, the float nose and stern molds are fastened to bars 292 and 294. Then between bars 290, 300 and 302 foam rubber or other plastic is poured. This material flows into the interstices between the casings within these bars, and also flows thru interstices between the forward and after larger-diameter float casings into the float nose and and stern molds and between the smaller casings there and between form 296 and the hollow core element 315. his core is of strong metal, has fastened to it the ends of tensile elements 6, and its sealed inner chamber contains air or, preferably, a light-weight gas such as helium.

In the next fabricating step the foam rubber is vuloanized, in an autoclave or by cold vulcanization.

Then the form bars and molds are removed and the structure turned upside-down. The flat, cushioning layer of foam rubber that forms the surface of its deck and the lower, top level of the two floats is now sealed over by paint and/or fabric. And the upper deck and sides of the boat are attached tothe tensile-element bolts at the end casings 304 of each horizontal row of the lower deck in the manner shown in FIGURE 1.

A fifth form of the boat, utilizing the basic invention, is shown in FIGURES 17 to 19. This craft is flat on the bottom and has an inflated, lighter-thanair, curved superstructure.

Its lower, floating part has two arcuate side walls, 314, that may be made of metal but preferably are formed of stearned-and-bent plywood. Between these walls there are strongly fastened cross pieces 315, of wood or metal; and to the forward portions of walls 314 there are fastened two other, arcuate members of wood or metal, 316. These members are also fastened to the ends of plank or bar 318, which is fixed to the middle one of pieces 315. These ends jut out from walls 314 a suflicient distance to mount outboard engines on and abaft bars 318. Secured to elements 318 by clamps, these engines provide a means for steering the boat-either by pivoting them or by varying their fuel intakes, under the control of the helmsman, who sits on seat 320.

The after ends of walls 314 are fastened to sternpost 322, which preferably is of Wood, and their forward ends to bow-bracing, wooden element 324. To these two posts the wooden (or metal) keel 326 is fixed. It is further fastened and braced in place by means of bolts 328, each of which has an integral screw at each of its ends; one of these screws is screwed into the keel and the other into a V-shaped bar, 330, that is bonded to the rubber of elements 332. The top edge of the keel is also 18 bonded to the tubular elements and to the foam rubber that fills the spaces between the curves of elements 332.

These elements may be rows of casings, assembled in the manner of those of FIGURE 1; but preferably they are formed of cylindrical (or, optionally, square) rubber extrusions. Each extrusion is cut at its ends to the shape of side walls 314; containers of helium, hydrogen, other light-weight gas or vacuums are inserted in the hollow space of the tube; this space is hermetically closed by bonding curved-edge rubber plates to the cut edges of the tubes ends; and then the element is lightly inflated and vulcanized.

In assembly of the lower, floating part of the boat, the stealmed plywood walls 314 are bent around the upsidedown planks or bars 315, which are held athwart the boat and correctly spaced in grooves in the horizontal top of a factory fixture. After securely fastening together these elements 314 and 315, tubular elements 332 are placed between the liquid-cement-coated, V-shaped edges of the upside-down planks. Then the keel is put in place, with elements 330 fitting in V-shaped grooves between inflated tubular elements; and the ends of the keel are cemented and screwed or otherwise strongly fixed to posts 322 and 324. Cement is also placed between the keel and the rubber surfaces of tubular elements 332 that contact the keel. Foam rubber is now poured into the V-shaped spaces between the tubular elements. It is dammed by the tightly contacting and comented surfaces of these elements and by side walls 314. The uncured rubber of this lowermost portion of the boat is now vulcanized; and this part is turned over, so that its keel rests in a long recess in the top of the fixture.

On the casings of the lower float portion, and within the upper rim of sidewalls 314 that projects above the casings, the main upper part or gunwale is now placed. it comprises plywood or metal side walls 333, joined and fastened together at each end, but with arcuate, upwardly-opened recesses there for the insertion of tubes of the balloon superstructure that will later be described. Between and to walls 333 there are fastened bracing ribs, 334, 335 and 336. Each of these is a piece of wood or metal that is fastened to 333 and also, along its lower edges, to one of the members 315. The second rib aft, 334, is arcuate in horizontal cross section, and at the center of its lower edge it is fixed, by means of metal angle braces, on top of thicker member 315. On the upper edge of this member 334 and also 011 the top edge of the forward transverse rib, a cover, 338, is fastened. This cover, arcuate ribs 334 and bulkheads 333 form a storage space at the bow, to which a small door in the arcuate rib gives access.

On the upper edge of rib 335, and also fastened to the middle portion of one of the ribs 336, seat 320 is supported. And the stern seat 340 is fastened to the two after ribs, 336. Two of the ribs 336 serve as back rests for the seats.

Six upright posts, 342, 344 and 345, are fixed to ribs 334, 335 and the forward one of ribs 336. The forward post, 342, is vertically recessed on each side for the reception and cementing of a pair of arcuate Windshields, 346, of transparent glass or plastic, which together encompass seat 320 and part of the space between the two seats. The top edges of the Windshields and posts are glued to an arcuate metal strip 348.

The lighter-than-air superstructure comprises spherical ballooned member 350 and arcuate, balloon-bracing, inflated tubes 352, 354, 356 and 358. These tubes are of inflatable, fabric-reinforced, vulcanized rubber material; preferably they comprise rubber extrusions that are welded at their open, cut ends to rubber disks 358. Each tube has an inflating-air valve, 360, and contains spherical, lighterthan-air units 362, of the above-described type. Optionally, these units may be otherwise curved.

Ballooned member 350 also contains lighter-than-air spheres, 364, floating in air that is admitted via valve 366. These spheres 364 preferably are not in a foam-rubber connected chain, but are covered with a thin coating of rubber. They may be of thin-walled metal, dense plastic or glass. The ballooned. elements rubber-and-fabric envelope 368 has two pairs of holes. Thru one pair the large bracing-and-lifting tube 352 extends, and thru the other pair tube 358 is threaded. At the holes these tubes and envelope 368 are sealingly bonded together with cement or vulcanized rubber compound. And the two tubes 354 and 356 that fit against and are cemented to the major portion of large tube 352 are also rubber-cemented to unperforated. portions of envelope 368. For clarity of illustration in FIGURE 18, tubes 352, 354 and 356 are shown without their streamlining envelopes. In the final assembly one of these outer skins envelope tube 356 and the after part of 352, and another envelope surrounds tube 354 and the forward part of 352. FIGURE 20 shows a cross section thru one of these final assemblies of tubes at the plane 20-24 of FIGURE 18. Fabric-reinforced rubber envelope 369 is held tautly around tubes 352 and 354 by their inflation. Around the forward portion of this envelope a loop of polyethylene rope or other cable, 370 is cemented. It is also cemented and stapled to cover 338. A similar loop, 372, is cemented around the after envelope and its assembly of tubes; it is connected to a length of rope, 374, which extends vertically downward to seat 34%), and then is curved aft and glued and stapled to this seat.

Tube 354 is cemented to the edge of an upwardlyopening, arcuate recess cut downward in the forward junction of side walls 333; and tube 356 is likewise fastened in a similar recess cut n the after rib 336. The forward and after ends of these tubes are housed and cemented within the junctions of walls 314 and are cemented to posts 322 and 324. Tube 352 is cemented to cover 338, the top of strip 348, the upper edge of post 370, and the middle of seat 340. And in the midship area the ends of tube 358 are housed between and cemented to the upper rims of walls 314 and the lower borders of walls 333. These tube ends are thus bracingly held between overlapping portions of the upper and lower sets of plywood wal-ls.

After these parts are assembled foam rubber is poured into this space between the overlapping Walls. This foam is then topped with a sheet of uncured, dense rubber compound; and the foam and the top layer are vulcanized. The whole of the boat is now coated with latex or other paint.

Within the scope of the subjoined claims various changes obviously may be made in the structure of the disclosed forms of the invention. For example, in the form of FIGURES 17 to 20 side walls 314 and 333 may be elongated aft of seat 340 and additional tubes 332 placed between the after ends of walls 314 and coated with rubber, thus forming an after deck. With this change, a single engine may be utilized, mounted on a rear transom. Another optional form of structure is to utilize repeated dipped-rubber-cement coats of the lighter-thanair units in lieu of the foam rubber that connects the spheres or cylinders in some of the other modifications. Ballooned element 350 will give some protection to users of the boat against hot sunshine or rain; if desired, this protection could be increased by placing and fastening one or more inflated, doughnut-shaped rings (containing lighter-than-air units) concentrically around envelope 368-either above or below the center of 350.

In the claims the word plastic is used to signify any type of natural or synthetic rubber or other plastic; the word gas to mean any pure gas or gaseous mixture; and the term material that is impermeable to gas to mean material thru which, at normal temperatures and atmospheric pressure, gas will not diffuse.

I claim:

1. A vessel having a flexible lower part that floats in water and an upper part that has lighter-than-air components, comprising:

a plurality of substantially airtight, inflatable receptacles, having walls of flexible material capable of repeatedly yielding under severe shock and returning substantially to their former configurations, said receptacles forming structural, strength-providing framework for said upper and lower parts, at least some of the receptacles being constructed and arranged to provide a useful-load-containing space;

compressed gas in said receptacles having a pressure greater than that of the atmosphere;

means holding said receptacles together;

and hollow, cavity-containing hermetically-sealed,

lighter-than-air units floatingly supported in the compressed gas within at least some of said receptacles of said upper part, each of said units having a clearance beneath its under side, relative to the flexible walls of one of said receptacles and being small enough to permit the unit to move into said clearance when the receptacle flexes at a point of contact between it and said unit, said units having thin walls of material that is impermeable to gas, and having substantial volume and lifting power above the vessels center of gravity.

2. A boat comprising:

a plurality of flexible substantially airtight, inflatable tubular elements, forming when inflated structural, strength-providing framework of the vessel and having walls comprising flexible plastic, at least some of said elements being grouped to provide a usefulload-carrying compartment within said framework;

means for inflating said elements with compressed gas at a pressure greater than that of the atmosphere;

cavity-containing, hermetically-sealed lighter-than-air units floatingly supported in the compressed gas within said walls, each having a substantial clearance beneath its lower surface, into which it moves when the wall above it flexes, and having thin shells of a material that is impermeable to gas.

3. Avessel having:

a part that floats in water and thus has a center of hydrostatic buoyancy, comprising a plurality of connected, inflatable, substantially airtight receptacles, having walls of flexible material capable of yielding under severe shock and returning to substantially their former configurations, said receptacles when inflated forming structural, strength-providing framework for said boat, and means for inflating said receptacles with gas at a pressure greater than that of the atmosphere; and

an upper part comprising a plurality of connected, in-

flatable, substantially airtight receptacles, having walls of flexible material capable of yielding under severe shock and returning to substantially their former configurations, said receptacles when inflated forming structural, strength-providing framework for said boat, at least some of said last-named receptacles containing hermetically-sealed lighter-thanair, cavity-comprising units, floatingly supported in compressed gas and having clearances within said walls, and having thin shells of material that is substantially impermeable to gas, said units thus pro viding a second, aerostatic center of buoyancy, and means for inflating said receptacles with gas at a pressure greater than that of the atmosphere;

the floating forces at said two centers of buoyancy being of such magnitude and relation of the positions of their centers as to provide a resultant center of buoyancy that is in a horizontal plane above that; of the vessels center of gravity.

4. A vessel as set forth in claim 3, in which said lighten than-air units have thin metal shells and contain lighte than-air gas.

5. A vehicle body comprising:

a plurality of substantially airtight receptacles, forming a structural, strength-providing part of the body and having walls of flexible material, capable of flexing under severe shock and returning to substantially their former configurations when the shock is over, and containing hermetically-sealed, non-collapsible lighter-than-air elements;

means for inflating said receptacles with compressed gas at a pressure greater than that of the atmosphere; and

means for holding said receptacles together, each of said lighter-than-air elements having beneath it, when its enveloping receptacle is inflated, a clearance into which the element may move when the receptacles walls flex under shock.

6. A device as set forth in claim 5, in which said means for inflating the receptacles comprises a valve on one of said receptacles and compressed, lighter-than-air gas.

7. A device as set forth in claim 5, in which at least some of said receptacles house cavity-containing lighterthan-air units which have walls of material that is impermeable to gas.

8. A device as set forth in claim 5, in which at least some of said receptacles are grouped to provide between them a compartment for carrying a useful load.

9. A device as set forth in claim 7, in which said compressed gas does not support combustion and in which said lighter-than-air units contain hydrogen, and are floatingly supported within said receptacles.

10. A device as set forth in claim 9, in which said material of the walls of the lighter-than-air units comprises glass.

11. A device as set forth in claim 7, which further comprises an element of foam plastic between each of said units and an upper, inside surface of one of said receptacles, and in which each of said units normally exerts its lifting force thru said plastic element and against said upper inside surface, and in which each unit is spaced from the other lighter-than-air units and has a clearance from the receptacles lower inside surface.

12. A device as set forth in claim 7, in which some of said receptacles are constructed and arranged to float said vehicle body on water and in which said flexible material. comprises flexible plastic.

13. A device as set forth in claim 12, in which at least some of said lighter-than-air units comprise containers of lighter-than-air gas.

14. A device as set forth in claim 12, in which said material of the lighter-than-air units comprises aluminum.

15. A device as set forth in claim 12, in which said material of the lighter-than-air units is magnalium.

16. A device as set forth in claim 12, in which said material of the lighter-than-air units is glass.

17. Avessel comprising:

a skin of waterproofed flexible material;

within said skin, a plurality of connected, hollow, in-

flatable, tubular elements, each element comprising a row of rubber-tire-like casings, means sealingly bonding together annular portions of the contacting sidewalls of said casings of each row, thus forming hermetically sealed annular cavities, and means closing and sealing the central openings in the outer sidewalls of the end casings of each row and thus closing the central hollow spaces in the aligned casings of each row;

compressed gas within each of said cavities and central hollow spaces having a pressure greater than that of the atmosphere; and

connecting means tautly holding together all said casings in each row, against the expanding pressure of said gas on their sidewalls.

18. A device as set forth in claim 17, in which the end casings of each row are vehicle rubber tires, and in 22 which the casings between said end tires are vehicle rub ber tires with portions cut out from their sidewalls.

19. A vehicle body comprising:

a skin of flexible material;

light-weight, porous, flexible plastic within said skin, constructed and arranged to provide an interior walled space for housing a useful load and an opening into said space from outside said body of sufficient size to allow the passage therethrough of a person; and

lighter-than-air units, having shells that are floatingly supported in said porous plastic, and exert a lifting force on said body.

20. A transportation vessel comprising:

an upper skin of flexible material;

light-weight, porous, resilient plastic within said upper skin;

lighter-than-air units, having shells that contain lighterthan-air gas, floatingly supported in said porous plastic, and exerting an aerostatic lifting force on said body;

a lower skin of flexible material, constructed and ar ranged to form the shell of means for floating the vessel in water, said means also comprising:

lighter-than-water porous plastic within said lower skin; and

hollow, airtight elements within said last-named porous plastic for providing additional buoyancy in said means for floating the vessel, said elements being filled with gas.

21. A transportation vessel having:

an upper, aerostatic-lift-providing body comprising: connected, flexible plastic tubes, sheathed in fabric; compressed gas inflating said tubes; and cavity-containing lighter-than-air units, having shells that are impermeable to gas and float in said compressed gas; and

a lower, floating body comprising plastic tubes, sheathed in fabric, and compressed gas within said last-named tubes;

at least some of said tubes being constructed and arranged to provide a useful load-containing space and an opening into said space of suflicient size to permit passage of a person.

22. A device as set forth in claim 21, in which said plastic tubes are rubber extrusions.

23. A water-traversing vessel comprising:

a lower, flotation-providing portion, at least the bottom part of which is adapted to be immersed in water, comprising a plurality of envelopes of flexible, waterproofed fabric, each of which is inflated and tensioned with gas of a specific gravity greater than that of helium at a pressure substantially greater than atmospheric pressure at sea level; and

an upper portion comprising at least one envelope of flexible, waterproofed fabric, inflated with gas of a specific gravity greater than that of helium at a pressure greater than atmospheric pressure at sea level, constructed and arranged to provide a useful-loadcontaining, interior chamber and an opening into said chamber of sufiicient size to permit passage of a person, and containing a plurality of hermeticallysealed, lighter-than-air elements of a weight per unit of volume that is less than that of said last-named gas; each of said elements comprising a thin nonporous sheath, and floating within and exerting a lift on said one envelope, and having a clearance below said sheath.

24. A device as set forth in claim 23, in which said lighter-than-air elements are permanently sealed containers of lighter-than-air gas.

25. A device as set forth in claim 23, in which said sheath is of metal.

26. A device as set forth in claim 23, in which said sheath is of glass.

27. A transportation vesselcornprising:

a skin of waterproof, flexible material;

within said skin, a plurality of inflatable, gas-filled,

tubular receptacles, having walls comprising flexible plastic and forming a structural, flexible, strengthproviding part of the vessel, said receptacles being juxtaposed and bearing against each other and of such number and total volume that when inflated with compressed gas the said walls, pressing and reacting against each other and against said skin, place the skin under tension; and

compressed gas, having a pressure substantially greater than sea-level atmospheric pressure, within the walls of each of said receptacles;

at least some of said gas-inflated receptacles being constructed and arranged to provide a useful-loadcontaining space and an opening from outside the vessel into said space of sufficient size for entry of aperson; and

a substantial portion of the gas in said last-named,

space-providing receptacles being located above the lower surface of said load-containing space.

28. A device as set forth in claim 27, in which said tubular receptacles further comprise projections which provide spaces between portions of said tubular elements, and in which said device further comprises foam plastic within said skin and in said spaces.

29. Aboat comprising:

a skin of waterproof, flexible material;

within said skin, a plurality of inflatable tubular receptacles, said receptacles being juxtaposed and bearing against each other, of such number and total volume that, when inflated against each other and against said skin, they place the skin under tension, and having walls comprising flexible plastic, thus forming a structural, flexible, strength-providing part of the vessel, in which at least some of said receptacles are constructed and arranged to provide a useful-loadcontaining space and an opening of suffioient size for entry of a person from outside the boat into said space;

compressed gas having a pressure substantially greater than sea-level atmospheric pressure within the flexible walls of each of said tubular receptacles; and 45 30. A device as set forth in claim 29, which further comprises foam-rubber conections between said containers.

31. Aboat comprising:

a skin of waterproof, flexible material;

within said skin, a plurality of inflatable tubular receptacles, each comprising a row of assembled, doughnut-shaped, inflatable elements, said receptacles being juxtaposed and bearing against each other, of such a number and total volume that when inflated, against each other and against said skin, they place the skin under tension, and having walls comprising flexible plastic, thus forming a structural, flexible, strength-providing part of the vessel, in which at least some of said receptacles are constructed and arranged to provide a useful-load-containing space and an opening of suflicient size for entry of a person from outside the boat into said space; and

compressed gas having a pressure substantially greater than sea-level atmospheric pressure within the flexible walls of said tubular receptacles, at least part of said gas being located within said elements.

32. A device as set forth in claim 31, in which each of said doughnut-shaped elements comprises a peripheral annulus and a pair of spaced ringlike sidewalls joined to said annulus at their outer peripheries and having openings at their centers, said device further comprising means for bonding the sidewalls together and disks that cover said openings at the end elements of each row.

References Cited by the Examiner UNITED STATES PATENTS 1,656,780 1/1928 Diago 24424 2,382,817 8/1945 Reiss 244-5 2,413,210 12/ 1946 Blackmail 114219 2,492,800 12/1946 Isom 24431 X 2,908,919 10/1959 Bicknell et al 911 3,067,712 12/1962 Doerpinghaus 11474 3,125,979 3/1964 Darling 114-219 FOREIGN PATENTS 255,488 3/1927 Great Britain.

MILTON BUCHLER, Primary Examiner.

FERGUS S. MIDDLETON, Examiner. 

1. A VESSEL HAVING A FLEXIBLE LOWER PART THAT FLOATS IN WATER AND AN UPPER PART THAT HAS LIGHTER-THAN-AIR COMPONENTS, COMPRISING: A PLURALITY OF SUBSTANTIALLY AIRTIGHT, INFLATABLE RECEPTACLES, HAVING WALLS OF FLEXIBLE MATERIAL CAPABLE OF REPEATEDLY YIELDING UNDER SEVERE SHOCK AND RETURNING SUBSTANTIALLY TO THEIR FORMER CONFIGURATIONS, SAID RECEPTACLES FORMING STRUCTURAL, STRENGTH-PROVIDING FRAMEWORK FOR SAID UPPER AND LOWER PARTS, AT LEAST SOME OF THE RECEPTACLES BEING CONSTRUCTED AND ARRANGED TO PROVIDE A USEFUL-LOAD CONTAINING SPACE; COMPRESSED GAS IN SAID RECEPTACLES HAVING A PRESSURE GREATER THAN THAT OF THE ATMOSPHERE; MEANS HOLDING SAID RECEPTACLES TOGETHER; AND HOLLOW, CAVITY-CONTAINING HERMETICALLY-SEALED, LIGHTER-THAN-AIR UNITS FLOATING SUPPORTED IN THE COMPRESSED GAS WITHIN AT LEAST SOME OF SAID RECEPTACLES OF SAID UPPER PART, EACH OF SAID UNITS HAVING A CLEARANCE BENEATH ITS UNDER SIDE, RELATIVE TO THE FLEXIBLE WALLS OF ONE OF SAID RECEPTACLES AND BEING SMALL ENOUGH TO PERMIT THE UNIT TO MOVE INTO SAID CLEARANCE WHEN THE RECEPTACLE FLEXES AT A POINT OF CONTACT BETWEEN IT AND SAID UNIT, SAID UNITS HAVING THIN WALLS OF MATERIAL THAT IS IMPERMEABLE TO GAS, AND HAVING SUBSTANTIAL VOLUME AND LIFTING POWER ABOVE THE VESSEL''S CENTER OF GRAVITY. 